Ore briquette



o. B. JONES. OREBRIQUFTTE. APPLICATION FILED JUNE 3, I9l8.

Patented May 9, 1922.

one BRIQUETTE.

Specification of Letters Patent.

Patented May 9,1922.

o l application filed June 22, 1914, Serial No. 846,468. Divided and this application filed June 3,

, To all whom it may concern:

Be it known that 1, DAVID B. Joivns, a

citizen of the United States, residing in which the following is a specification, refer-' ence being had to the accompanying drawings, forming a part thereof.

hily invention is more specifically con-c ce'rned' with the production of zinc, and the following specification is described in connection therewith, but it will be understood that in some respects, and particularly in its broader aspects, it is also applicable to other ores. t relates to the form and also to the construction and composition of briquettes by reason of which they are particularly adapted for use in a certam process forming the subject-matter of a Patent No. 1,292,330, granted tome January 21, 1919, on an application of which the present application is a division, and in a new andimproved type of furnace shown and described but not claimed insaid patent, and form ng the subject-matter of another application No; 237,867 of even date herewith.

Briefly described said furnace comprises a heating chamber in the hearth, of which are arranged or formed inclined guides leading from the charging end of the furnace to the exit end thereof, along which the briquettes are tice of said composed largely of the ore and a reducing material, are subjected to a temperature which distills off the zinc, and surrounded by an oxidizing atmosphere by which the zinc vapor given off is converted into the oxide, carbonate or both, and collected as such. My improved briquette is rounded, and in the preferred form spherical, which permits it to roll along said guides no matter how placed thereon, the period of its transit through the furnace being sufficiently extended and the temperature of the furnace such as to substantially drive off all the zinc contained in the briquette without, however, driving off any lead or silver which the ore may contain. The spherical form of briquette also has the advantage that it conduces to equal heating and expansion throughout so that no such strains are set up during the heating as would tend to split up and disintegrate the briquette. In order to make a substantial briquette which Wlll fed bygravity, and in, thepracprocess the briquettes, which are Serial No. 237,868.

stand up, under the treatment to which it is subjected and not readily disintegrate, I employ with the mixture of ore a reducing agent or a binder preferably of inorganic matter, and coat the briquette with a relatively thin layer of refractory material which is sufficiently pervious to permit the escape of the zinc vapors therethrough.

flln the accompanying drawings Fig. 1 is a vertical longitudinal section of a furnace designed for the treatment of my improved.

briquettes and as covered in the aforesaid application of even. date; Fig. 2 is a Vertical transverse section thereof on the line 22 of Fig. 1; Fig. 8 an inclined transverse section parallel to the hearth of the furnace on the line 3 3 of Fig. 1; and Fig. 4 is a cross sectionillustrating the improved briquette.

Referring first to Figs. 1, 2 and 3, the furnace comprises the usual side walls and roof arranged however at an incline, but the hearth or bottom of the furnace is composed oflongitudinal extending piers or walls A spaced slightly apart and supported with respect to each other by the interposed blocks or bricks a. The upper edges of the walls are oh amfered or cut away as shown in Fig. 2, to form between each pair of adjacent walls a track or runway down which the briquettes B travel. In the particular furnace shown there arenine of these runways, but obviously this number might be increased or diminished accordingto the capacity of furnace desired. At the upper or front end of the furnace an opening or doorway C is provided in register with each track or runway, and is closed by a suitable door, and at the lower or discharge end of the furnace a door D normally closes the opening opposite each track. At suitable intervals to provide the proper length of treatment for each briquette a new briquett e is inserted at the upper end of each track or runway, and the end briquette at the lower end of such runway permitted to drop into a storage chamber E from which the briquettes may be removed as they accumulate. The furnace is heated by means of gas and air, the air being conveyed to transverse chambers X extending transversely of the piers or walls forming the hearth by means of perforated pipes F extending from a longitudinal pipe F leading from the blower F and gas being supplied to said transverse chambers by transverse perforated pipes G connected to a longitudinal main Gr leading to some suitable supply of fuel gas. The flame and heated products of combustion not only heat the longitudinal pier walls, but rising between and about the briquettes B heat them to the desired temperature. Preferably the heat fromthe briquettes B in the chamber E is used to pre-heat the air used in connection with this furnace, andfor this purpose the fan F supplying air is connected to the chamber E and the longitudinal pipe F likewise opens thereinto so that the air previous to its passage to the burner pipes is heated to a considerable temperature. The

' zinc distilled from the briquettes may be collected in any suitable manner, but preferably I provide an additional supply of air for oxidizing it and collect it in the form of the oxide, the air being supplied to the chamber H above the briquettes through a branch of sufficient quantity when mixed with water or other liquid to firmly unite the particles of ore and reducing material. After the mixture above described has been made the briquettes are formed, preferably, in

molds under very high pressure, and are then permitted to dry until they are sufliciently rigid for further treatment. They are then covered with a slip of fire clay or a light refractory material by dipping or otherwise, after which they are slowly heated and dried to drive off all the contained moisture preparatory to charging the briquettes, into the furnace.

It will be found that the relative amounts of ore reducing agent and binder will vary with the particular ore used, and the 1 best proportions may be readily determined by experiment. Instead of water alone a solution of common salt may be employed for bringing the materials into plastic form and for making a slip or grout with which the briquettes are covered,

the salt remaining in the briquettes after the water has been driven off and acting in a measure as a flux. Any'form of press may be used which will furnish the desired pressure to produce great compactness and solid-v ity in the briquettes, and any form of kiln may be used for drying the briquettes,

though preferably they are dried quite slowly and at a temperature of about 220 degrees Fahrenheit, which temperature ordinarily twenty-four hours or longer is required to complete the drying operation. The drying may be done either before or after the application of the coating of fire clay, but if done mainly before such application it is preferable to again dry the briquettes suiliciently to drive ofi the moisture imparted by the application of the fire clay.

In the furnace the briquettes are gradually raised to a temperature at which the zinc oxide or other zinc compound contained in the briquettes is reduced by the powdered coal or other reducing agent and volatilized. But the zinc vapors coming into the oxidizing atmosphere maintained in the furnace are converted intothe oxide and the fumes collected in any of the-devices commonly employed in pigment furnaces for such purposes. v

. As many zinc ores also contain compounds of lead or silver or both it is preferable to keep the temperature of the furnace below that at which these metals are volatilized, and after the briquettes have been substantially deprived of their zinc content they may'be' given further treatment in ordinary vertical furnaces or the like for recovering the other valuable metal contents thereof.

Obviously certain advantages of my improved briquette may be obtained in furnaces other than those of the type just described, the superior resistance of the briquettes due to their composition, construction and form being valuable in many of the old and well-known types of furnace, and it is not absolutely essential to feeding the brick through the furnace by gravity that theybe spherical so long as they are substantially circular in cross-section though if they are not spherical care must be taken that they be so placed in the guides or runways as to roll down the same when the lowermost briquettes are withdrawn.

Iclaim:

l. A briquette composed of zinc ore, a reducing agent and, a binder ofbauxite.

2. A briquette composed of zinc ore, a reducing agent, a plastic inorganic binder and common salt.

3. A briquette comprising'a mixture of zincore, reducing material, and a binder, and having a slip coating of pervious highly refractory material thereon.

4. A briquette comprising a mixture of zinc ore, reducing material and a binder, having a coating of fire clay thereon.

DAVID B, JONES. 

